So many people want to swear that
English Bulldog breeders are mix breeding & hanging papers to
get Merle Bulldogs. Most believe whatever they are told, or what
they read without any backing to prove the belief, yet they
still believe it & will actually accuse others of wrongdoing
without any facts to back up the accusation.

That is pretty sad since there are
many VERY reputable breeders that have a conscience &
ethics....so I have compiled some info here, that can be backed
up with science, and by Professionals with the education to
state what is correct.

We are not so misinformed, though
that we do not realize that there are breeders who HAVE cheated,
mixed, and hung AKC papers taking shortcuts to get the Merle in
their program. This makes it even harder for the ethical breeder
of Purebred AKC Merle English Bulldogs.

As for our breeding program, we have
parentage DNA with AKC on all our dogs associated with our Merle
Program. Our Merles are PUREBRED AKC Bulldogs
(English Bulldogs). AKC themselves list ALL Breeds in connection
with the Merle pattern as do others as you will see below.

This page is not just my opinion. Every word on this page has
been taken from articles of Scientists, Geneticists, Doctors,
etc. all of which can be found by the links at the bottom of
this page. It took me 5 months to read & go through all the
websites & articles and excerpt the pertinent info that applies
here.

Merle can be hidden by other genes, and patterns, sometimes for
long periods of time. This is why the merle gene can & has
ALWAYS been in EVERY breed and is backed up by scientific fact.

Hidden merles are merle dogs who do not
exhibit the merle pattern because their coat color does not show
the pattern. Merling is not normally shown in red, gold, fawn
and cream coat colors. The hidden merle can be
distinguished only by a genetic test.

1. Recessive Red

Merle can be
completely hidden by recessive red, as recessive red dogs can't
make eumelanin pigment and merle only affects eumelanin. A
recessive red merle is known as a phantom merle.

2. Sable

A clear sable (dog with a red coat, but
no visible black sabling) will also not show any merling because
there is no eumelanin to be merled, unless it also has a mask
(which does show merling).

Shaded sables will often show merle at
birth, but it tends to fade as the dog grows up, so all that
remains on an adult is usually a few darker brownish patches on
the coat (which can be hidden very easily by thick or long fur).

3. The greying gene can also make it
very difficult to see merle markings.

4. The dilution gene (dd), because it
dilutes the patches to roughly the same color as the base.

5. Brindle

Merle can be very difficult to see on
a brindle too, due to the stripes.

6. Heavy Markings

Merle
can be hidden if the dog has very heavy markings, so a black
merle could appear completely black if the patches are large
enough (a cryptic merle).

Dogs with cryptic merle (also called phantom or ghost
merle), typically display little to no merling and some may be
misclassified as non-merles.

Inheritance of merle is genetically unstable for bothMandMcalleles.
During DNA replication and cell division,Mmay
occasionally undergo poly-A tail reduction to produceMc(germline
rate of 3-4%) whileMcmay undergo
expansion and revert toM. Because of the
complexities of merle inheritance, and potential health
concerns, DNA testing is recommended to establish the genetic
make-up of dogs for the merle gene for those breeds where this
color dilution pattern is present.

The Veterinary Genetics Laboratory is licensed to offer the
merle test.

Screenshots of TOP Scientific Labs, Registries & Universities
that include MERLE in ALL BREEDS of Dog.

Quotes from Doctors &
Scientists

In talking to breeders and doing additional research,
it is apparent that this color pattern is not new. Up to recent
time a dog with the merle color pattern was described as
spotted, mottled, incorrectly as brindle, and in some incidences
not addressed in the color description of the dog at all.

Clemson University Canine Genetics Research
Laboratory

Dr. Leigh Anne Clark and her team, who mapped and
sequenced the merle gene in 2005, tell us that it is the same
gene in all breeds. She and her fellow genetic researchers draw
the conclusion that “the breeds analyzed in this study (the
mapping /sequencing study) share a common ancestor,” and that
“the occurrence of merle in many breeds . . . suggest that the
founding mutation may predate the divergence of breeds.”

Revising Breed Standards

I believe the standard of any breed should undergo
revision when genetic information and science dictate.

Articles published in scientific journals in recent
years have added new information to our understanding of the
merle gene. Why would we close our eyes to this new educational
opportunity? Why not apply what we know now?

“Those who say we should not be accommodating the
Standard to what we are breeding, or that our present Standard
was outlined by our founding fathers, need to review all the
Standard changes since the mid 1800’s . . . I would like to
think that we make changes in the Standard to clarify certain
areas for breeders and judges as well as to correct errors as we
gain more knowledge, especially in areas of genetics and
inheritance.”

The M locus is the home of the merle allele. Merle is
dominant, and so denoted by the capital letter M. Non-merle is
recessive, and denoted by m.

Merle is interesting because all normal merles
are heterozygous (Mm). A homozygous merle is actually a double
merle.

Merle affects only eumelanin. That means that any
black, liver, blue or lilac in the coat, eyes or nose will be
merled, whether it's the whole of the body, a mask on a sable,
shading, brindle stripes, or even a saddle. Phaeomelanin (red)
is not affected at all and will appear as normal.

Most Black based Merle dogs are called "blue
merles" because of the bluish color between the patches in their
coat. This is a widely-used term but is actually misleading.
Technically they should be "black merles". Their nose pigment is
black and their eyes are brown or blue. They are able to make
normal eumelanin in their coat, so their patches are black. If
they didn't have the merle gene, they would be solid black.
"Blue merle" is misleading because it seems to say that these
dogs have blue pigment (dd acting on black), when in fact they
have black.

The random coat dilution caused by merle also affects
the eyes and nose. The eyes may be all or partly blue, and
the nose may be all or partly pink. Not all merles have blue
eyes or pink noses though, and merles with heavy dark patching
are more likely to have normal eye and nose pigment.

Due to the unstable and variable nature of the merle
gene, sometimes merles have patches that are only partially
diluted, and are between the base and the patch color. These are
known as dilute spots, and they may sometimes appear brownish.
Dogs with very extensive dilute and/or brown patching are likely
to be tweed merles.

We talk about coat color being "diluted" in a merle,
but note that dilute spots don't have anything at all to do with
the Dilution gene (d), and are just a normal variation of the
merle pattern.

Merle acts on the black pigment in the iris of the eye
just as it does on the coat, so merle dogs often have part or
all of the eye blue. (This does not affect their vision, though
since it happens to some extent in the retina as well it may
make it harder to diagnose certain eye problems.)

There are always two copies of a gene, alike or
different, in any dog. If we call the merle gene M and the
non-merle gene m, any given dog can be mm, Mm or MM. The mm dog
is the normal. The Mm dog is a blue merle, chocolate merle,
lilac merle, black merle, or sable merle, depending on what
color it would have been without the merling gene. An MM dog,
often called a double merle or a homozygous merle, will be
mostly white and sometimes can be associated with deafness or blindness.

Breeding merle to full color will produce one half full
color and one half merles, but no defective whites. The merle to
full color breeding, then, produces just as many merles as does
the merle to merle breeding, and without the danger of defective
puppies. The safe breeding for a merle, then, is to a non-merle
mate. This breeding should produce all healthy puppies, and
about half will be merles.

Sable merles are no more likely to have health problems
than any other color. The real argument against sable merles is
that they may be mistaken for normal sables. If two such sable
merles were mated together, the resulting litter could contain
defective whites. What a shock for the breeder that may produce
lethal whites.

Very few breeders have been lucky enough to get high
quality homozygous (double) merles that are not too severely
affected to breed - but it definitely takes a lot of luck and
really top quality black merles to start with. Merle to merle
breedings are only for the very experienced breeder who knows
his/her lines and what they will produce, and it has probably
produced more heartbreaks than good homozygous merles, even for
the experienced breeder.

There is no such thing as a sable, blue, chocolate,
lilac, or black merle gene. There is only a merle gene. Merle is
a dilution gene, that is, it lightens whatever the coat color
would otherwise have been. The lightening is not spread evenly
over the coat, but leaves patches of undiluted color scattered
over the dog's body. Also, the lightening seems to work
primarily on the black pigment in the coat, so any tan on the
face stays even.

Cryptic merle

Cryptic merle (phantom merle) are dogs that show only
very slight merle coloration and in some cases it is not visible
at all. The dog can have only small patches of merle, for
example, at the end of tail or ear or the merle coloration can
be concealed by white markings.

These dogs carry the shorter version of the merle gene,
sometimes one copy and sometimes two copies. Unlike regular
merle dogs, in the cryptic merle dogs no serious health problems
connected with the regular (not shortened) merle allele have
been described. They apparently have no eye or hearing
problems. Dogs with two copies of cryptic merle gene (Mc/Mc
genotype) or dogs with one cryptic merle copy and one regular
merle copy (M/Mc genotype) have no health problems. The correct
description of cryptic merle is a problem when registering the
dog. These dogs appear like normal colored and are usually
registered as non-merle dogs since not every breed registry
color code includes the merle pattern as a choice.

Frequent mistakes: Excessive white markings in puppies
from a tri-to-merle cross are not an indication that the puppy
is a cryptic merle. The genetics of excessive white markings is
completely different and have nothing to do with merle gene.

In breeding, a cryptic merle can be mated only with
non-merle dogs (like dogs with regular merle allele). When
crossed, the cryptic allele may expand again to regular
non-shortened merle allele. When mating a cryptic merle (Mc/N)
with a non-merle (N/N) you can find puppies with the following
genotypes: Cryptic merle/non-merle (Mc/N), Merle/ non-merle
(M/N), non-merle/non-merle (N/N).

Hidden merle

Hidden merles are merle dogs who do not exhibit the
merle pattern because their coat color does not show the
pattern. Merling is not normally shown in red, gold, fawn and
cream coat colors. The hidden merle can be distinguished
only by a genetic test.

Recessive red and merle can be a dangerous combo,
simply because you may not know that a recessive red dog is a
merle. The two genes occur together in a number of breeds,
including Pomeranians and Chihuahuas, and in such breeds it's
advisable to never breed a clear red dog (with any merle in its
ancestry) to a merle, due to the risk of accidentally breeding
double merles.

Getting your dogs tested for Merle
eliminates this problem.

Clear sable can "hide" merle almost as effectively as
recessive red. A clear sable is one with no dark (eumelanin)
hairs in its coat, and clear sables may be almost
indistinguishable from recessive reds. For this reason, care
should be taken when breeding any solid red dogs in breeds where
merle is present.

Prevention

Genetic testing for merle gene is highly recommended in
order to avoid severe health problems that may occur when merle,
cryptic merle and hidden merle dogs are crossed incorrectly or
in case of risky breeding. The genetic test reveals the merle,
the hidden merle and the cryptic merle variants.

All puppies that appear as "non-merle" at first sight
have to be properly checked for any less visible merle patches.
If such patch is found, it is not a non-merle, but a cryptic
merle. In particular, the small merle patch can disappear in
long or thick hair. Later, such dog can be mated with another
cryptic/hidden merle dog unintentionally. So the breeders can
run unintentional risks of producing double merle dogs.

Merle Modifiers

A merle modifier is a gene that, when inherited along with
merle, will affect the way the merle pattern appears. A dog with
a merle modifier but no merle gene will not be affected at all.
It's thought that merle modifiers are inherited separately from
merle and appear on their own locii. Merle Modifiers:
Tweed,
Harlequin, &
Pseudo Harlequin